Motorized vascular sealer override device

Abstract

A surgical clip for sealing tissue, the surgical clip including a housing having a drive rod having an end effector, the end effector including a first jaw member and a second jaw member, the first jaw member and the second jaw member configured to seal tissue when the end effector is electrically activated. A stationary handle depends from the housing and is configured to support a clamp override actuator operably coupled to the motor. The movable handle is operably coupled to the drive rod and is movable relative to the fixed handle through an initial range of motion to move the drive rod such that the jaw members pivot relative to each other to grasp tissue therebetween. The movable handle is configured to contact the gripping override actuator through a further range of motion to actuate the gripping override actuator such that the motor engages the drive rod to further move the drive rod to create a higher gripping force to seal tissue.

Description

Technical Field

[0001] The present disclosure relates generally to the field of surgical instruments. In particular, the present disclosure relates to an in-line endoscopic electrosurgical clamp that is economical to manufacture and capable of sealing and cutting tissue structures. Background Art

[0002] For tissue sealing, the surgeon typically must generate sufficient clamping force before initiating energy delivery, which can lead to fatigue with repeated use in the case of in-line devices. In addition, in-line devices typically do not have a locking feature, further requiring the surgeon to hold the jaws in the "clamped" position until the generator recognizes that sealing is complete.

[0003] Instruments such as electrosurgical clamps are commonly used in open and endoscopic surgical procedures to coagulate, cauterize, and seal tissue. Such clamps typically include a pair of jaw members that can be controlled by a surgeon to grasp target tissue, such as a blood vessel. The jaw members can be approximated to apply a mechanical clamping force to the tissue, and the jaw members are associated with at least one electrode to permit electrosurgical energy to be delivered to the tissue. The combination of mechanical clamping force and electrosurgical energy has been demonstrated to link adjacent tissue layers captured between the jaw members. When the adjacent tissue layers include the wall of a blood vessel, sealing the tissue can result in hemostasis, which can facilitate transection of the sealed tissue.

[0004] Bipolar electrosurgical clamps typically include opposing electrodes disposed on the clamping faces of the jaw members. The electrodes are charged to opposite potentials so that electrosurgical current can be selectively passed through tissue grasped between the electrodes. To achieve a proper seal, particularly in relatively large blood vessels, two primary mechanical parameters must be accurately controlled; the pressure applied to the vessel and the gap distance established between the electrodes.

[0005] Both pressure and gap distance affect the effectiveness of the resulting tissue seal. If sufficient gap distance is not maintained, there is a possibility that the opposing electrodes will contact each other, which may cause a short circuit and prevent energy transfer through the tissue. Moreover, if the applied force is too low, the tissue may have a tendency to move before an adequate seal can be produced. The thickness of a typical effective tissue seal is optimally between about 0.001 inches and about 0.006 inches. Below this range, the seal may shred or tear, and above this range, the vessel wall may not be effectively connected. The closing pressure for sealing large tissue structures is preferably about 3 kg / cm 2 About 16 kg / cm 2 within the range.

[0006] In-line electrosurgical clamps are a common type of electrosurgical instrument that provides the ease of electrically activating the clamp by fully and continuously compressing the same handle used to close the jaw members around tissue. In some cases, the surgeon may only wish to grasp tissue without electrically activating the jaw members. Thus, it is desirable to manufacture an in-line electrosurgical clamp that facilitates both grasping tissue and in-line activation. Summary of the invention

[0007] According to the present disclosure, there is provided a surgical clamp for sealing tissue, the surgical clamp comprising a housing having an elongated drive rod having an end effector assembly disposed at a distal end thereof, the end effector comprising a first jaw member and a second jaw member configured to seal tissue when the end effector is electrically activated. A fixed handle is suspended from the housing and is configured to support a clamp override actuator disposed in the fixed handle, the clamp override actuator being operably coupled to a motor. A movable handle is operably coupled to the drive rod and is movable relative to the fixed handle through an initial range of motion to move the drive rod when the movable handle is actuated without contacting the clamp override actuator, so that one or both of the first jaw member or the second jaw member pivots relative to the other of the first jaw member or the second jaw member to grasp tissue therebetween. The movable handle is configured to contact the clamp override actuator through an additional range of motion to actuate the clamp override actuator so that the motor engages the drive rod to move the drive rod further to generate a higher clamping force to seal the tissue. The clamp override actuator is disposed in the actuation path of the movable handle.

[0008] In aspects according to the present disclosure, the clamp override actuator includes an encoder configured to communicate to the motor that the clamp override actuator has been contacted by the movable handle, thereby identifying that the motor is mechanically engaged with the drive rod.

[0009] In various aspects according to the present disclosure, the clamp override actuator includes a key operably connected to the clamp override actuator, the key being movable with the clamp override actuator, the key being configured to push one or more gears from the motor into engagement with one or more corresponding gears on the drive rod. In other aspects according to the present disclosure, the motor includes a gear box disposed on the drive shaft, the gear box being configured to cooperatively engage with a corresponding series of gears disposed on the drive rod.

[0010] In aspects according to the present disclosure, the clamp override actuator is biased against a spring disposed within the fixed handle.

[0011] In various aspects according to the present disclosure, the movable handle can be moved about the pivot through an initial range of motion to force the drive collar against the drive rod to pivot the jaw members relative to each other for grasping tissue. In other aspects according to the present disclosure, the drive collar compresses the spring against the drive collar stop to adjust the grasping pressure between the jaw members. In still other aspects according to the present disclosure, the clamp further includes a position encoder, which is disposed proximate to the drive collar stop and is configured to report the position of the drive collar stop relative to the position encoder during sealing. In still other aspects according to the present disclosure, the clamp includes a force sensor, which is disposed on a portion of the drive rod proximate to the drive collar stop and is configured to sense a linear force on the drive rod during sealing.

[0012] According to the present disclosure, there is provided a surgical clamp for sealing tissue, the surgical clamp comprising a housing having an elongated drive rod having an end effector assembly disposed at a distal end thereof, the end effector comprising a first jaw member and a second jaw member configured to seal tissue when the end effector is electrically activated. A fixed handle depends from the housing and is configured to support a clamp override actuator disposed in the fixed handle, the clamp override actuator being operably coupled to a motor. A movable handle is operably coupled to the drive rod and is movable relative to the fixed handle through an initial range of motion, which causes the drive rod to move when the movable handle is actuated, causing one or both of the first jaw member or the second jaw member to pivot relative to the other of the first jaw member or the second jaw member to grasp tissue between the first jaw member and the second jaw member at a first clamping pressure by pivoting the drive collar against a drive stop. The movable handle is configured to transition to an override position through an additional range of motion to actuate a clamp override actuator so that the motor engages the drive rod to move the drive rod further to generate a higher clamping force to seal tissue. The clamp override actuator is disposed in the actuation path of the movable handle.

[0013] In aspects according to the present disclosure, the clamp override actuator includes an encoder configured to communicate to the motor that the clamp override actuator has been contacted by the movable handle, thereby identifying that the motor is mechanically engaged with the drive rod.

[0014] In various aspects according to the present disclosure, the clamp override actuator includes a key operably connected to the clamp override actuator, the key being movable with the clamp override actuator, the key being configured to push one or more gears from the motor into engagement with one or more corresponding gears on the drive rod. In other aspects according to the present disclosure, the motor includes a gear box disposed on the drive shaft, the gear box being configured to cooperatively engage with a corresponding series of gears disposed on the drive rod.

[0015] In aspects according to the present disclosure, the clamp override actuator is biased against a spring disposed within the fixed handle.

[0016] In various aspects according to the present disclosure, the movable handle can be moved about the pivot through an initial range of motion to force the drive collar against the drive rod to pivot the jaw members relative to each other for grasping tissue. In other aspects according to the present disclosure, the drive collar compresses the spring against the drive collar stop to adjust the grasping pressure between the jaw members. In still other aspects according to the present disclosure, the clamp further includes a position encoder, which is disposed proximate to the drive collar stop and is configured to report the position of the drive collar stop relative to the position encoder during sealing. In still other aspects according to the present disclosure, the clamp includes a force sensor, which is disposed on a portion of the drive rod proximate to the drive collar stop and is configured to sense a linear force on the drive rod during sealing.

[0017] According to another embodiment of the present disclosure, a method for sealing tissue by motorized assistance is provided, and includes the following initial steps: orienting tissue between a first jaw member and a second jaw member of an end effector assembly, the end effector assembly being supported at the distal end of an elongated drive rod extending from a housing. The method further includes: moving a movable handle through an initial range of motion relative to a fixed handle suspended from the housing so that the drive rod moves so that the jaw members approach to grasp tissue disposed between the jaw members under a first pressure; moving the handle through an additional range of motion to transition to an override position of the movable handle so as to actuate a clamp override actuator, the clamp override actuator engaging a motor with the drive rod, the motor being configured to release the movable handle from the drive rod and further move the drive rod to generate a higher clamping force for sealing tissue; and releasing the clamp override actuator when sealing is completed to disengage the motor and reengage the movable handle with the drive rod to open the jaw members to release tissue when the movable handle moves. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate embodiments of the present disclosure and, together with the detailed description of the embodiments given below, serve to explain the principles of the present disclosure.

[0019] Figure 1 is an interior side view of an in-line electrosurgical clamp according to an embodiment of the present disclosure, the electrosurgical clamp including a housing, an elongated shaft, an end effector assembly having opposed jaw members, and a movable handle;

[0020] FIG. 2A to FIG. 2C yes Figure 1 Different views of the movable handle of the clamp and the internal components therein, showing different ranges of gripping positions;

[0021] Figure 2D and Figure 2E yes Figure 1 Different views of a movable handle of a clamp and internal components therein showing activation of a clamp override through a continuous range of motion of the movable handle, thereby activating a motor to provide a higher clamping force to tissue disposed between the jaw members;

[0022] Figure 2F yes Figure 1 An interior side view of the clamp showing the movable handle releasing the clamp override and releasing tissue;

[0023] Figure 3 is an enlarged internal view of another embodiment of an electrosurgical clamp including a motor-driven override according to the present disclosure; and

[0024] FIG. 4A to FIG. 4D is a different interior view showing the movable handle and internal mating components of the override device to provide a higher clamping force to tissue disposed between the jaw members when actuated. DETAILED DESCRIPTION

[0025] First reference Figure 1 , the electrosurgical clamp 100 generally includes a housing 112 that supports a variety of actuators thereon for remotely controlling an end effector 114 via an elongated shaft 116. Although this configuration is typically associated with instruments used for laparoscopic or endoscopic surgical procedures, various aspects of the present disclosure may be practiced with respect to conventional open instruments and also in conjunction with endoluminal procedures. The housing 112 is constructed of left and right housing halves as perceived by an operator using the clamp 100, and may be constructed of a sturdy plastic that is joined to one another by adhesive, ultrasonic welding, or other suitable assembly methods.

[0026] To mechanically control the end effector 114, the housing 112 supports a fixed handle 120 and a movable handle 122. Typically, a trigger and a rotation knob are included in the design of the clamp 100 for reciprocating the knife to cut tissue disposed between the jaw members and for rotating the jaw members, but for the sake of brevity, the trigger and the rotation knob are not described herein. A detailed discussion of these features can be found in commonly owned U.S. Patent No. 7,255,697, the entire contents of which are incorporated herein by reference.

[0027] The movable handle 122 is operable to move the end effector 114 in an open configuration ( Figure 1 ) (wherein a pair of opposing jaw members 130, 132 are disposed in a spaced relationship relative to one another), different degrees of gripping configuration, and movement between clamping positions for sealing tissue (such as Figures 2A to 2E ). Approaching of the movable handle 122 relative to the fixed handle 120 is used to move the end effector 114 to the grasping configuration and the closed configuration, and separation of the movable handle 122 from the fixed handle 120 is used to move the end effector 114 to the open configuration.

[0028] To electrically control the end effector 114, the fixed handle 120 supports a depressible button 137 thereon that is operable by a user to both control the clamping pressure and to initiate and terminate the delivery of electrosurgical energy to the end effector 114 to seal tissue, as explained in more detail below. More particularly, the button 137 is engageable by the proximal side of the movable handle 122 when the movable handle 122 is moved proximally to an actuated position or proximal position. The button 137 includes a base ring disposed within the fixed handle 120 that is configured to be slidably received in the fixed handle against the force of a spring 139 when the handle 122 is moved to the proximal position for actuation (see FIG. 2C to FIG. 2E ), the purpose of which will be explained below. The button 137 is in electrical communication with the motor 300 and the electrosurgical generator "G" via appropriate electrical wiring (not explicitly labeled) extending from the housing 112 through the cable 143, which extends between the housing 112 and the electrosurgical generator "G". The generator "G" may include devices such as the LigaSure® vessel sealing generator and the ForceTriad® generator sold by Covidien. The button 137 can be configured to control only the motor 300, and a separate switch (not shown) can be used to control the electrosurgical activation of the jaw members 130, 132 to seal tissue.

[0029] The end effector 114 can be moved from an open configuration ( Figure 1) (wherein tissue "T" is received between jaw members 130, 132), a series of grasping positions (wherein the surgeon handles and manipulates tissue "T") ( Figures 2A to 2B ) moves to the clamped configuration ( Figures 2C to 2E ) (wherein the tissue "T" is clamped at a force necessary to seal the tissue). The jaw members 130, 132 pivot about the pivot pin 144 to move the end effector 114 between the positions. In order to provide an effective tissue seal, a force of about 3 kg / cm2 may be applied to the tissue. 2 About 16 kg / cm 2 and typically around 7 kg / cm 2 About 13 kg / cm 2 . Moreover, in the closed configuration, a separation or gap distance of about 0.001 inches to about 0.010 inches is maintained between jaw members 130, 132, and a separation or gap distance of about 0.003 inches to about 0.006 inches can be typically provided. In some embodiments, any suitable number, arrangement and / or configuration of stop members (not shown) can be provided on the inwardly facing surface of jaw members 130, 132 made of heat-resistant ceramic according to a specific purpose.

[0030] Jaw members 130, 132 are electrically coupled to cable 143, and thus to generator "G" (e.g., via corresponding appropriate electrical wiring extending through elongated shaft 116) to provide electrical access to jaw members 132, 130. Once a tissue seal is established, a blade (not shown) may be advanced to transect the sealed tissue.

[0031] Overall reference Figure 1 , a movable handle 122 is pivotally coupled to a drive collar 115 including a proximal stop 117a and a distal stop 117b within a housing about a pivot 111. The drive collar 115, when moved by actuation of the handle 122, causes an internally disposed drive rod 105 to translate within an axis 116, which in turn causes the jaw members 130, 132 to move between an open position, a gripping position, and a closed position. More specifically, the distal end of the drive rod 105 actuates a drive pin 103 disposed within a pair of corresponding cam slots 130a, 132a disposed within the jaw members 130, 132 to cause the jaw members 130, 132 to move by cam action to a closed configuration around the tissue "T".

[0032] As described above, when the surgeon actuates the handle 122, energy may be applied by in-line actuation to seal tissue. For a typical in-line enabled instrument, when the movable handle 122 is moved to a fully actuated or proximal position, the proximal portion of the handle (or an element extending therefrom) depresses the button 137, thereby enabling the generator "G" to deliver electrosurgical energy to the end effector 114 to deliver energy for tissue treatment. As described above, for tissue sealing, the surgeon typically must generate a high clamping force before initiating energy delivery, which in the case of an in-line device requires the surgeon to maintain a high clamping force during the sealing cycle, which may cause fatigue, especially during repeated sealing cycles.

[0033] like Figure 1 As shown and described above, the motor 300 is disposed within the housing 112 and can be operably coupled to a generator "G" or some other internal or external power source (not shown). The motor 300 includes a shaft 310 that drives a motor coupler or gearbox 315. The gearbox 315, in turn, includes a series of gears 318 that are configured to operably engage with a set of corresponding gears 106 disposed on the proximal end of the drive rod 105. The key 141 extends from the gearbox 315 and is operably coupled to the button 137. The key 141 is configured to move the gears 318 into engagement with the gears 106 to relieve the force required to clamp the tissue "T" as soon as the handle 122 reaches a specific position, as explained in more detail below.

[0034] Reference now FIG. 2A to FIG. 2E As described above, the surgeon moves handle 122 from an open position, through a series of gripping positions, to a clamping position for sealing, which in turn moves jaw members 130, 132 from a first position (wherein jaw member 130 is spaced from tissue "T" disposed therebetween) to a second position (wherein jaw member 130 is spaced from tissue "T" disposed therebetween). Figure 1 ), second position (wherein both jaw members slightly contact the tissue to firmly grasp the tissue "T") ( FIG. 2A to FIG. 2C ) moves to a third position (wherein tissue "T" is clamped under appropriate pressure to create a tissue seal) ( FIG. 2D to FIG. 2E ). The motor 300 relieves the surgeon of the gripping force before electrical activation. In other words, the surgeon FIG. 2A to FIG. 2C The in-line activation feature of the clamp 100 relieves the surgeon from excessive force and the internal motor 300 generates the clamping force by actuating the drive rod 105 before generating the necessary force required to seal the tissue.

[0035] More particularly, as described above, button 137 includes a base ring 138 that is slidingly received in fixed handle 120 against the force of spring 139 such that when handle 122 is actuated to the proximal position, button 137 and base ring 138 move into fixed handle 120 and abut against spring 139 (see FIG. 2C to FIG. 2E The base ring 138 moves relative to a position encoder 125 disposed within the fixed handle 120, which is configured to provide feedback to the motor 300 regarding the relative position of the button 137, thereby instructing the motor 300 to activate and engage the drive rod 105 as soon as the button 137 is fully depressed, i.e., the surgeon's grip handle 122 has passed the sufficient removal position "O" (see Figure 2C and Figure 2E ). In addition to the motor 300 being activated via an instruction from the encoder 125, when the handle 122 is grasped to the position "O" ( Figure 2C ) and as base ring 138 moves past encoder 125, key 141 is moved to engage gear 318 of gear box 315 with gear 106 of drive rod 105 so that drive shaft 310 of motor 300 can drive drive rod 105 in direction “S” to clamp jaw members 130, 132 and relieve or unburden handle 122 and the surgeon from the higher force required to seal tissue ( Figure 2D and Figure 2E ).

[0036] As can be appreciated, the surgeon freely grasps and manipulates tissue "T" with relatively light tissue pressure between jaw members 130, 132 to avoid damaging the tissue during manipulation of the tissue, thereby requiring the surgeon's hand to apply relatively light handle pressure, e.g., much lower than the pressure required for blood vessel sealing (approximately 3 kg / cm 2 About 16 kg / cm 2 Once the surgeon has selected the tissue "T" to be sealed, the surgeon simply grasps the tissue "T" between the jaw members 130, 132 to position "O" and activates the motor 300 to clamp the tissue "T" and activate the Ligasure ® The surgeon maintains control of the handle 122 and the motor 300 (and the motor 300 assists in maintaining the sealing pressure), but applies only minimal pressure to the handle 122, thereby greatly reducing surgical fatigue.

[0037] In use, and as Figures 1 to 2FAs shown, the surgeon initially positions tissue "T" between jaw members 132, 130. Movement of drive rod 105 to cam jaw members 130, 132 to the gripping position is proportional to the relative movement of handle 122 about pivot 111 relative to fixed handle 120. In this initial gripping range of motion, motor 300 and motor drive shaft 310 are initially disengaged from drive rod 105 until button 137 is engaged, as explained above. The surgeon then moves the jaw members 130, 132 to the gripping position. FIG. 2A to FIG. 2C As shown, the handle 122 is grasped relative to the fixed handle 120 without actuating the button 137 to manipulate the tissue "T", thereby applying a gradually increasing grasping pressure to the tissue "T". In this way, the surgeon is free to grasp and manipulate the tissue until the sealing site is determined ( Figures 1 to 2B ). A typical system using a 1:1 ratio of handle movement to jaw movement is contemplated. As more gripping pressure is applied, the drive collar 115 gradually separates from the proximal collar stop 105b against the bias of the spring 113 .

[0038] The position encoder 129 records the relative position of the distal collar stop 105a of the drive rod 105 relative to the encoder 129, which can be used to evaluate the seal quality during or after the sealing cycle. A force sensor 105c can also be included to sense the linear force on the drive rod, which can be used to evaluate the seal quality during or after the sealing cycle.

[0039] Once the tissue sealing site is determined, the surgeon grasps the handle 122 relative to the fixed handle 120 and applies grasping pressure until position "O" ( Figure 2C ). At this point, the motor 300 relieves the pressure requirement on the handle 122 and is operably coupled to the drive rod 105. More specifically, at position "O", two operations are initiated simultaneously (or substantially simultaneously): a first operation, the button 137 is actuated by the proximally facing portion of the handle 122 to push the key 141, thereby engaging the gear 318 of the gearbox 315 of the motor 300 with the gear 106 on the drive rod 105; and a second operation, the encoder 125 is instructed to communicate to the motor 300 that the button 137 has been moved and the motor 300 is now engaged with the drive rod 105.

[0040] Once the encoder 125 senses that the button 137 has been moved and the motor 300 is engaged, the motor 300 initially moves the drive rod 105 to a position such as the rotation of the drive shaft 310 and the gear 318. Figure 2D137. The fully clamped or fully grasped position is shown. At this point, the tissue "T" is fully grasped and under the control of the motor 300 (as opposed to being controlled by the handle 122 for manipulation). It is important to note that the surgeon still has the option of releasing the handle 122 from the button 137, which will disengage the motor 300 and reallocate operational control back to the handle 122 for additional grasping and manipulation if desired.

[0041] If the surgeon wishes to use LigaSure ® The surgeon further actuates handle 122 through encoder 125, which is in communication with motor 300, to further rotate drive shaft 310 and gear 318 to move gearbox 315 and drive rod 105 distally and move jaw members 130, 132 by camming at greater pressure to seal tissue. 2 About 16 kg / cm 2 Once the proper sealing pressure is provided between the jaw members 132, 130, a signal may be sent to the generator "G", or a sealing cycle may be automatically initiated for a particular purpose. Alternatively, the surgeon may manually initiate the seal by enabling a switch (not shown). The shaft position sensor 129 and force sensor 105c may be utilized to help improve the seal quality by providing various feedback controls to the motor of the generator "G" during the sealing cycle.

[0042] Once the seal is complete, the surgeon simply releases the handle 122, and the spring 113 returns the drive rod 105 proximally, which in turn returns the jaw members 130, 132 to a more open orientation. The motor 300 may be configured with a reverse gear (not shown) to facilitate the initial opening of the jaw members 130, 132 according to a particular purpose. As the surgeon begins to release the handle 122 relative to the handle 120 and as the base ring 138 moves distally along the encoder 125 (i.e., after a successful sealing cycle), the motor 300 may begin to reverse and begin to release tissue "T" from the jaw members 130, 132. Reversing the motor 300 will rotate the drive shaft 310 in the opposite direction, which in turn will retract the drive rod 105 proximally (and the gearbox 315 proximally) and move the jaw members 130, 132 to a more open position through cam action.

[0043] Once button 137 is disengaged from handle 122, encoder 125 will instruct motor 300 to stop the reverse gear, and simultaneously key 141 will release gear 318 from gear 106, thereby allowing handle 122 to resume operational control of drive rod 105 and jaw members 130, 132, and handle 122 will reset to the state as shown. Figures 1 to 2C Gripping and manipulating capabilities shown.

[0044] It is important to note that during sealing, the surgeon maintains the same gripping pressure with button 137 engaged, but the sealing pressure is generated by motor 300 to seal the tissue. Thus, during procedures with repeated sealing cycles, surgical fatigue is minimized while still providing surgical safety because the surgeon can choose to release jaw members 130, 132 at any time by releasing button 137 and disengaging motor 300.

[0045] Steering Figure 3 , which shows a device configured to relieve the surgeon's gripping force or LigaSure prior to electrical activation ® Another embodiment of the force override device 400 motor. Similar to the clamp 100 and override device 300 described above, the surgeon can FIG. 2A to FIG. 2C The in-line activation feature of the clamp 100 and override device 400 also alleviates the surgeon from excessive force before generating the necessary force required to seal the tissue, and the internal motor 400 generates the sealing force by actuating the drive rod 105.

[0046] Figure 3 The clamp 100 of the embodiment is similar to the clamp 100 described above and is therefore briefly summarized herein and only those features that differ will be described in detail. The movable handle 122 is operable to move the end effector 114 between an open position and a closed position ( Figure 4A and Figure 4D ). The handle 120 supports a two-stage button 137 that activates electrosurgical energy and controls the grasping, clamping and sealing pressure.

[0047] As described above, when the surgeon actuates handle 122 to grasp, manipulate, and ultimately seal tissue, the surgeon must overcome the spring force of the handle, which is necessary to generate the force required to seal. Once the desired tissue is positioned and clamped between jaw members 130, 132, energy is applied to seal the tissue by further actuating handle 122 relative to handle 120 through in-line actuation. Typically, during a sealing cycle using an in-line device, the surgeon must generate and maintain a high clamping force before initiating energy delivery, which can lead to fatigue, especially with repeated sealing cycles.

[0048] Figure 3The clamp 100 of FIG. 1 shows another embodiment configured to alleviate this problem by providing an override device 400. The override device 400 includes a motor 402 enclosed in a motor housing 401 and configured to drive a rotating shaft 404. The shaft 404 is in turn coupled to a distal screw 405 having a screw head 410 that is slidingly disposed within a proximal shaft connector 415. A seal or guide 420 controls movement of the shaft 105 into the connector 415.

[0049] A toggle 135 connects the proximal portion of the handle 122 with the proximal end of the drive carriage 107, which is configured to support the drive rod 105, the drive collar 115, and the drive spring 113 between the drive stops 105a, 105b. The toggle 135 supports sliding movement of the drive carriage 107 along a track 119 defined in the proximal end of the housing 112 during actuation of the handle 122.

[0050] refer to FIG. 4A to FIG. 4D The operation of the override device 400 is described. Figure 4A The handle 122 is shown in an unactuated position with the jaw members 130, 132 fully open for assessing and manipulating tissue. The carriage 107 is disposed in a distal-most orientation and the screw head 410 is disengaged from the proximal shaft connector 415, ie, the motor 402 is not engaged.

[0051] Figure 4B Handle 122 is shown actuated relative to handle 120 but not engaged with button 137. Thus, as handle 122 rotates, handle 122 drives spindle 115 against the force of spring 113 to move carriage 107 proximally along track 119 under the guidance of toggle 119, thereby pulling drive shaft 105 proximally to move jaw member 130 around tissue relative to jaw member 132 by cam action. In this case, spring 113 is a low compression spring because high compression forces for sealing tissue do not need to be generated, thereby minimizing surgeon fatigue under continuous use. Low compression springs are defined as having a compression force in the range of about XXXXX N to about XXXXX N.

[0052] Figure 4CIn-line actuation (indicated by a single-headed arrow) is shown with handle 122 actuated to a first stage "1", wherein electrosurgical energy is activated and the clamping force is increased via motor 402. More particularly, when activation button 137 is activated, electrosurgical energy is activated along with motor 402 to rotate rotary shaft 404 in direction "R", which pulls screw head 410 against proximal shaft connector 415. In this way, motor 402 overrides or disengages control handle 122 and pulls drive shaft 105 proximally, thereby generating additional closing force to cam jaw members 130, 132 against tissue. As can be appreciated, this relieves the surgeon of the burden of generating force for sealing tissue.

[0053] Figure 4D In-line actuation (indicated by the double-headed arrow) with handle 122 actuated to the second stage "2" is shown, wherein electrosurgical energy is still activated via activation of button 137, and motor 402 generates a higher force "H" by further rotating rotation shaft 404 in direction "R" (which pulls screw head 410 against proximal shaft connector 415). This in turn pulls drive shaft 105 proximally, thereby generating LigaSure between jaw members 130, 132. ® Sealing force "L" is generated to seal the tissue therebetween. Likewise, motor 402 overrides or disengages control handle 122 and pulls drive shaft 105 proximally, thereby generating the force necessary to seal the tissue between jaw members 130, 132. Again, this relieves the surgeon of the burden of generating the force for sealing the tissue.

[0054] Once the tissue is sealed and the surgeon proceeds as described above FIG. 2A to FIG. 2D When handle 122 is released in a similar manner as described above, override device 400 and motor 402 are deactivated, and handle 122 resumes control of jaw members 130, 132 to release tissue.

[0055] Although several embodiments of the disclosure are shown in the accompanying drawings, it is not intended to limit the disclosure thereto, as it is intended that the scope of the disclosure be as wide as the art will allow, and this specification should be read in the same manner. Therefore, the above description should not be construed as limiting, but rather as merely illustrative of specific embodiments. Those skilled in the art will envision other modifications within the scope and spirit of the appended claims.

[0056] Although the foregoing disclosure has been described in some detail by way of illustration and example, for purposes of clarity or understanding, it will be apparent that certain changes and modifications may be practiced within the scope of the appended claims.

Claims

1. A surgical clamp for sealing tissue, comprising: a housing including an elongated drive rod having an end effector assembly disposed at a distal end of the elongated drive rod, the end effector including a first jaw member and a second jaw member configured to seal tissue when the end effector is electrically activated; a stationary handle depending from the housing and configured to support a clamp override actuator disposed therein, the clamp override actuator operably coupled to a motor; as well as a movable handle operably coupled to the drive rod and movable relative to the fixed handle through an initial range of motion to move the drive rod when the movable handle is actuated without contacting the clamp override actuator so that at least one of the first jaw member or the second jaw member pivots relative to the other of the first jaw member or the second jaw member to grasp tissue between the first jaw member and the second jaw member, the movable handle being configured to contact the clamp override actuator through an additional range of motion to actuate the clamp override actuator so that the motor engages the drive rod to move the drive rod further to generate a higher clamping force to seal tissue, Wherein, the clamp override actuator is arranged in the actuation path of the movable handle.

2. The surgical clamp for sealing tissue according to claim 1, wherein: The clamp override actuator includes an encoder configured to communicate to the motor that the clamp override actuator has been contacted by the movable handle, thereby identifying that the motor is mechanically engaged with the drive rod.

3. The surgical clamp for sealing tissue according to claim 1, wherein: The clamp override actuator includes a key operably connected to the clamp override actuator, the key being movable therewith, the key being configured to urge at least one gear from the motor into engagement with at least one corresponding gear on the drive rod.

4. The surgical clamp for sealing tissue according to claim 3, wherein: The motor includes a gear box disposed on a drive shaft and configured to cooperatively engage a corresponding series of gears disposed on the drive rod.

5. The surgical clamp for sealing tissue according to claim 1, wherein: The clamp override actuator is biased against a spring disposed within the fixed handle.

6. The surgical clamp for sealing tissue according to claim 1, wherein: The movable handle is movable about a pivot axis through the initial range of motion to force the drive collar against the drive rod to pivot the jaw members relative to each other for grasping tissue.

7. The surgical clamp for sealing tissue according to claim 6, wherein: The drive collar compresses a spring against a drive collar stop to adjust the gripping pressure between the jaw members.

8. The surgical clamp for sealing tissue according to claim 7, further comprising a position encoder disposed proximate to the drive collar stop and configured to report a position of the drive collar stop relative to the position encoder during sealing.

9. The surgical clamp for sealing tissue according to claim 7, further comprising a force sensor disposed on a portion of the drive rod proximate to the drive collar stop and configured to sense a linear force on the drive rod during sealing.

10. A surgical clamp for sealing tissue, comprising: a housing including an elongated drive rod having an end effector assembly disposed at a distal end of the elongated drive rod, the end effector including a first jaw member and a second jaw member configured to seal tissue when the end effector is electrically activated; a stationary handle depending from the housing and configured to support a clamp override actuator disposed therein, the clamp override actuator operably coupled to a motor; as well as a movable handle operably coupled to the drive rod and movable relative to the fixed handle through an initial range of motion, which, when the movable handle is actuated, moves the drive rod so that at least one of the first jaw member or the second jaw member pivots relative to the other of the first jaw member or the second jaw member to grasp tissue between the first jaw member and the second jaw member at a first clamping pressure by pivoting a drive collar against a drive stop, the movable handle being configured to transition to an override position through an additional range of motion to actuate a clamp override actuator so that a motor engages the drive rod to move the drive rod further to generate a higher clamping force to seal tissue, Wherein, the clamp override actuator is arranged in the actuation path of the movable handle.

11. The surgical clamp for sealing tissue according to claim 10, wherein: The clamp override actuator includes an encoder configured to communicate to the motor that the clamp override actuator has been contacted by the movable handle, thereby identifying that the motor is mechanically engaged with the drive rod.

12. The surgical clamp for sealing tissue according to claim 10, wherein: The clamp override actuator includes a key operably connected to the clamp override actuator, the key being movable therewith, the key being configured to urge at least one gear from the motor into engagement with at least one corresponding gear on the drive rod.

13. The surgical clamp for sealing tissue according to claim 12, wherein: The motor includes a gear box disposed on a drive shaft and configured to cooperatively engage a corresponding series of gears disposed on the drive rod.

14. The surgical clamp for sealing tissue according to claim 10, wherein: The clamp override actuator is biased against a spring disposed within the fixed handle.

15. The surgical clamp for sealing tissue according to claim 10, wherein: The movable handle is movable about a pivot axis through the initial range of motion to force a drive collar against the drive rod to pivot the jaw members relative to each other for grasping tissue.

16. The surgical clamp for sealing tissue according to claim 15, wherein: The drive collar compresses a spring against a drive collar stop to adjust the gripping pressure between the jaw members.

17. The surgical clamp for sealing tissue according to claim 10, further comprising a position encoder disposed proximate to the drive collar stop and configured to report a position of the drive collar stop relative to the position encoder during sealing.

18. The surgical clamp for sealing tissue according to claim 10, further comprising a force sensor disposed on a portion of the drive rod proximate the drive collar stop and configured to sense a linear force on the drive rod during sealing.

19. A method of sealing tissue with motorized assistance, comprising: orienting tissue between first and second jaw members of an end effector assembly supported at a distal end of an elongated drive rod extending from the housing; moving a movable handle relative to a fixed handle depending from the housing through an initial range of motion to move the drive rod to approximate the jaw members to grasp tissue disposed between the jaw members at a first pressure; moving the handle through an additional range of motion to transition to an override position of the movable handle to actuate a clamp override actuator that engages a motor with the drive rod, the motor configured to release the movable handle from the drive rod and further move the drive rod to generate a higher clamping force for sealing tissue; as well as Releasing the clamp override actuator when sealing is complete disengages the motor and reengages the movable handle with the drive rod to open the jaw members to release the tissue as the movable handle moves.

20. A surgical clamp for sealing tissue, comprising: a housing including a fixed handle depending from the housing and an elongated drive rod having an end effector assembly disposed at a distal end of the elongated drive rod, the end effector including a first jaw member and a second jaw member configured to seal tissue when the end effector is electrically activated; as well as A movable handle, which is operably connected to the drive rod and can be moved through an initial range of motion relative to the fixed handle to cause the drive rod to move against the bias of the low compression spring when the movable handle is actuated so that at least one of the first jaw member or the second jaw member pivots relative to the other of the first jaw member or the second jaw member to grasp tissue between the first jaw member and the second jaw member, and the movable handle can be moved through an additional range of motion relative to the fixed handle to actuate an override device to engage the motor with the drive rod and disengage the handle from the drive rod to allow the drive rod to move further to generate a higher force between the jaw members for clamping or sealing tissue between the jaw members.

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